Malachin G, et al. – Aim was to illustrate the combined action of human commensal bacteria and amorphous silica nanoparticles on the viability and immune responses of dendritic cells. In this study, the simultaneous exposition to engineered or environmental nanoparticles (NPs) appeared to alter the inflammatory and immune action of dendritic cells (DCs) stimulated by commensal bacteria agonists.